diff --git a/configure.in b/configure.in
index e1fa786c2..4de466cf4 100644
--- a/configure.in
+++ b/configure.in
@@ -792,7 +792,7 @@ else
 	AC_MSG_ERROR([not found])
 fi
 AC_MSG_CHECKING([for gid of group "$ipsecgroup"])
-ipsecgid=`$EGREP "^$ipsecgroup" /etc/group | $AWK -F: '{ print $3 }'`
+ipsecgid=`$EGREP "^$ipsecgroup:" /etc/group | $AWK -F: '{ print $3 }'`
 if test -n "$ipsecgid"; then
 	AC_MSG_RESULT([$ipsecgid])
 	AC_SUBST(ipsecgid)